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Ken <Ken@invalid.com>: Dec 04 08:17PM -0600 > If it does beep it is probably not the clock generator, provided you > are looking aty the right chip. What's the number anyway ? Maybe I'll > have a go at getting some info on it.   Sure did try it without RAM. Even tested the RAM in another computer. The clock generator is a SLG8LP625T Thanks.

stratus46@yahoo.com: Dec 04 08:56PM -0800 On Thursday, December 4, 2014 5:04:50 AM UTC-8, Ken wrote: > stratus46@yahoo.com wrote: <snip> > Searching the web, I found others with the same type of problem on the > same model of computer. That does not mean there is a common problem, > but it does mean I am not alone.   The thing to remember about ESR meters is that they can be fooled by parallel ceramic bypass caps so it can read good when it is in fact bad. If it reads bad it likely is. Bulging is a good indicator and ruptures have likely sprayed acid around the board.   I started using solid polymer caps instead of 'lytics on mobos at work and they're doing well. My 4 newer machines at home are all polymers and no 'lytics. I expect no problems before obsolescence.   IF you decide to change caps, go for the highest ripple current / lowest ESR and stay away from cheap junk.   G²

jurb6006@gmail.com: Dec 05 07:18AM -0800 >"Sure did try it without RAM."   OK, that was the specific information I wanted. the RAM is cleared as well as a possibly corrupted RAM controller. Sometimes those things take a virus or a cosmic ray or something and it needs to reset completely to straighten it out. (not kidding anymore about the cosmic ray, I recently read an article on exactly that corrupting memory)   I didn't find the sheet on that chip. This is one of those things that would probably require emailing Silllyonics or whoever made the thing and all that. However it does seem there are suppliers. What is the case style ? Is it something that doesn't take a million dollar rework station to change ? (like a BGA) If it's not that bad you might just try popping one in. Also if there is a crystal nar the thing change that as well, in fact maybe change that first as it is easier. If you can find it, if it is not built into the IC, if if if, of course.   And as stra...@yahoo said, make sure about the caps. hat I ddo sometimes is to determine which are in the same bank. Of course all the grounded sides read continuity, but when you get continuity on the other (usually +) lead, those are all in one bank. Then for testing purposes I just put in one. I don't even trim the leads, I leave them long and just see if the damthing works. If it does then I start changing the bunch of them. One hting about oscillators, if the power going to it isn't well bypassed it might just not work. Depends on how it is configured.   I assume since you said it is not clocking that you have seen AOME DC on the pins. If all the pins have 0V it is kinda obvious. (I run the scope in DC mode for things like this for reasons like that, then I know already)   This now depends on how good the board is. If you can get the same model generic you MIGHT be able to migrate the OS to it and avoid a reload, but I cannot say if it would have to come from Overpriced.com, err I mean HP. They might not have made the board. Like this Dell I got in the boneyard, ECS motherboard. Thought you were buying a good PC from a reputable source ? Well ECS is about ½ step down from Foxconn, meaning elcheapo. I would have replaced this ECS if I could get a fair price on it, which I consider to be about twenty bucks. I would get a decent Gigabyte or something but I wouldn't be able to reregister the OEM Windows 7 to it. So to the boneyard with it. Your HP is probably the same deal, you'll need a copy of Windows if you change it to a totally different type of board. (of course with Linux you wouldn't have that problem but that is beside the point)   Yup, caps, chip and crystal and if that doesn't do it, it is probably for the boneyard. You still have drives and a PS and all that right ?

Ken <Ken@invalid.com>: Dec 05 10:13AM -0600 > Yup, caps, chip and crystal and if that doesn't do it, it is probably > for the boneyard. You still have drives and a PS and all that right > ?   All of what you say about the project is true. I have spent more time on it than it is worth, but I am a persistent person who believes "the answer is out there." I think I shall look for a scrap computer of the same model that has a good MB but the rest of it is NG. A new MB costing $200-300 is out of the question.   Finally, like you said about there being no voltage on the other pins of the clock generator: It would be obvious as to why it did not work. There were DC levels and the cap next to the chip was at the 3.3v supply the chip needed. I thought someone might have some source of info about the clock generator that would confirm my belief that it should be free running. Thanks to you and the others for their comments.

jurb6006@gmail.com: Dec 05 07:42AM -0800 No chorus. The rate pot has been changed, and it appears successful but messy. It is a slightly different pot but seems right enough I would think. It is a 100K. On it I have a negative DC voltage, varies at the wiper.   I do not know if the pot was bad, maybe the last guy put in the wrong one. Or maybe it is the right one and he erroneously replaced it but it didn't fix it. I have no way of knowing this.   It is pretty sure that the LFO (oscillator) is not working. When you adjust the depth pot there is a change in the sound which indicates the variable filters, VCAs whatever are working.   One thing would be nice is a print. I have one but it is poor quality.   https://dl.dropboxusercontent.com/u/29948706/fender_power_chorus.rar   A better one would help, in fact probably ANY print of that section in an amp using the same chorus circuit.   Thanks. I am not as adept at reverse engineering as I used to be. Blind in one eye and can't see out the other. In my heyday some would joke that I could do this with my eyes closed. And now... LOL

N_Cook <diverse@tcp.co.uk>: Dec 05 03:48PM > https://dl.dropboxusercontent.com/u/29948706/fender_power_chorus.rar   > A better one would help, in fact probably ANY print of that section in an amp using the same chorus circuit.   > Thanks. I am not as adept at reverse engineering as I used to be. Blind in one eye and can't see out the other. In my heyday some would joke that I could do this with my eyes closed. And now... LOL   Is this a "digital" pot the wiper feeds an ADC ?

jurb6006@gmail.com: Dec 05 07:31AM -0800 Squealing. More volume, more squealing. Quite annoying.   Pretty obvious it needs filters. Can't seem to find service info on the thing though. I think I can do it without but I would really like to see how it comes apart before tearing in to it. It has the flip top like a laptop and you know how those can be. I don't want to screw it up, rip the main ribbon to the lid or anything like that.   Actually I am doing music equipment now, amps, mixers etc. and am not actually finding as many bad caps as in brownwares. More bad solder joints etc. Is there ac chance that's the problem here ? If I had history on it, if the problem used to be intermittent, great.   At first I figured this lil thing has to be class D, but a post on the net alludes to it using LM3866 which is not. Who knows right now ? At this point though, both channels are doing it so I am leaning toward the PS. As small as this thing is, I will probably have to search Digikey for good enough, snall enough caps for it.   Seriously though, right now I am concerned about getting in there without killing the patient. Anyone have one of those things apart ?   Thanks.

KenO <kenitholson@yahoo.com>: Dec 04 01:14PM -0800 Have a fully discharged Nokia BL-5J 1430 mAh 3.7 Battery that would like to safely test for charge retention.   Did some forum searching and found some general info.   Did not find anything concerning:   1. how to test if the battery fuse and protection circuit is intact. Just guessing that if infinite Ohms something is blown but have no idea what the normal Ohms should be.   2. Use another battery to try to charge the Nokia to get it above the charger cutoff point?   Hope someone has solved this problem and would like to share any tips.   Googled and found "Li-ion should never be discharged too low, and there are several safeguards to prevent this from happening. The equipment cuts off when the battery discharges to about 3.0V/cell, stopping the current flow. If the discharge continues to about 2.70V/cell or lower, the battery's protection circuit puts the battery into a sleep mode. This renders the pack unserviceable and a recharge with most chargers is not possible. To prevent a battery from falling asleep, apply a partial charge before a long storage period."   Also found by another Ken who does not want to share his method "On February 4, 2011 at 2:21pm Ken wrote: The article mentions how dangerous it is to attempt charging cells that have been @<1.5v for just a few days. Well, that has not been in agreement with my experience. I occasionally salvage discarded Li-ion laptop battery packs...disassembling them to harvest the 18650's for personal r/c and flashlight use. I commonly pull cells that are totally flat: 0v, sometimes even with polarity reversed by a few millivolts. In addition, some of the battery packs I ripped into were prehistoric by lithium chemistry standards (10 years+). More often than not all cells would recharge to their FULL original rated capacity and perform as new. I always test each cell individually with my iMAX B6 charger, manually putting them through at least a couple 500mA to 1Amp discharge/charge cycles. I have *never* experienced any safety nor reliability issues to date. I would also like to brag of having had success restoring substantial capacity to the occasional cells that truly were worn. I will never share my method_IT'S MINE !_do not ask. ...Additionally, that procedure IS potentially dangerous and requires mandatory attentive supervision. I suppose I've been laughing all the way to the battery bank. I know, horrible joke!" http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries   Thanks   Ken

mike <ham789@netzero.net>: Dec 05 12:05AM -0800 On 12/4/2014 1:14 PM, KenO wrote:   > Thanks   > Ken   No idea about your battery, but here are some of the issues. It probably has a protection circuit. If it has been discharged below threshold, it's turned off and cannot be turned on externally. You'll see zero volts and high ohms.   Disclaimer: What follows is for educational purposes only. DO NOT DO IT! IT's unsafe.   IF you take the battery apart, you can get past the circuit board and connect directly to the cell, you can charge it. If I were to ever do this unsafe procedure, I might start with 100 mA charge current voltage limited at about 3.7V depending on the exact chemistry involved. Do NOT get in a hurry...do not set it up and go away...watch it, through your safety glasses, for any signs of overheating. You need a laboratory supply with precise control of the current and voltage limits. DO not rely on some marking on a wall wart. NEVER, EVER TRY TO CHARGE ONE BATTERY FROM ANOTHER BATTERY! You risk setting yourself on fire. The protection circuit is there for a reason. I'd put it in a metal pot with a lid so I'd have a handle to use to carry it outside if it catches fire. THIS IS NOT A SAFE PROCEDURE.   At this point, I might try charging it in the phone.   Sometimes, the protection circuit will NOT reset. If it's still dead, give up, you've done all you can do.   Even if you're successful, you are still at risk. Maybe your phone will catch fire weeks from now.   Bottom line, go buy a new battery. They're much cheaper on ebay than the cost of a hospital visit or a burned-down house.

Tim R <timothy42b@aol.com>: Dec 05 06:46AM -0800 I came across an interesting thread on a flashlight battery explosion.   http://www.candlepowerforums.com/vb/showthread.php?120888-ROAR-of-the-Pelican-(CR123-Explosion-during-use-firsthand-account)   Read down to page 5, where the delayed effects of HF poisoning hit the victim. I understand he has never recovered fully.

etpm@whidbey.com: Dec 04 09:55AM -0800 On Tue, 2 Dec 2014 16:44:10 -0500, "Maynard A. Philbrook Jr." >> Eric   >Try replacing the Power Supply!   >Jamie You did notice that this is an electronics REPAIR group, right? Eric

Michael Black <et472@ncf.ca>: Dec 04 01:58PM -0500

"Maynard A. Philbrook Jr." <jamie_ka1lpa@charter.net>: Dec 04 06:45PM -0500 In article <dv718ade9jmos0oe8jikcns7d3erdhoidm@4ax.com>, etpm@whidbey.com says...   > >Jamie > You did notice that this is an electronics REPAIR group, right? > Eric   Sure did and if you knew what you were talking about you would know that cost of labor investigating internals of a power supply over simply just replacing it has a broad dollar value. Labor is expensive but the cost of a replacement supply or just simply plugging in a test unit is much cheaper   Next time, think , think, and think again before opening the trap.   Jamie

etpm@whidbey.com: Dec 04 04:32PM -0800 On Thu, 4 Dec 2014 18:45:12 -0500, "Maynard A. Philbrook Jr." >much cheaper   > Next time, think , think, and think again before opening the trap.   >Jamie Since I'm going to repair it I have decided the labor is worth it. I suppose I should have said that I was going to repair this power supply. I did not say if I had looked in the power supply. I should have because I did. But it seems like I did not look closely enough. This weekend I'll take another look and hopefully find a bulging cap that I can replace. Eric

stratus46@yahoo.com: Dec 04 09:07PM -0800 > This weekend I'll take another look and hopefully find a bulging cap > that I can replace. > Eric   You can buy a 500 W power factor corrected supply from Newegg for $40 and THEN get a $15 rebate. Buying good caps to redo your old supply will run $5-$10 and we haven't added the value of your time. Add another $5-$10 for a new cooling fan and you see how they are disposable.   You must be young enough that the 'satisfaction' of repairing it has value but you'll get over it. Personally I replace power supplies but replace caps on motherboards to get going again. Repair the things that are hard to replace.   Also there are nasty Voltages in the power supply but none on the mobo.   G²

Tim R <timothy42b@aol.com>: Dec 05 06:11AM -0800 > You must be young enough that the 'satisfaction' of repairing it has value but you'll get over it. Personally I replace power supplies but replace caps on motherboards to get going again. Repair the things that are hard to replace.   > Also there are nasty Voltages in the power supply but none on the mobo.   > G²   There is some satisfaction in the learning process itself though.   I hadn't realized at first but now obviously this is a PC but not a laptop. So I don't know if my observation applies here at all. But given our history with the kids's school laptops, the power supply and the power jack seem to be weak links. We've gone through a number of replacement wallwarts or equivalent, and have had several where the power jack connection eventually fails.   I guess there's no point making them bulletproof when the PC is obsolete in a few years, but it sure is annoying to have an otherwise workable machine unusable because you can't power it up.

Phil Allison <pallison49@gmail.com>: Dec 04 05:21PM -0800 Arfa Daily wrote:   > In my workshop, I have four four-drawer filing cabinets absolutely > jam-packed with service manuals that I have collected over more than 40 > years in the business.   ** Wow, I have hardly any after 40 years in the same business.   Here in Australia, service manuals for most pro audio products have long been hard to get and/or cost real money. The info (other than a schematic) provided in the vast majority is so poor as to be worthless. I am thinking of manuals from Crown, Yamaha, QSC, Phase Linear and others.   One problem is that the folk who write these manuals are never service techs. Often the product designer is given the job or some one associated with the design team who picked the short straw. If you have never made your living doing bench servicing, how in hell can you expect to advise those that do ?   Another problem is that at the time of writing, no actual products have been sold so none of the product's design faults or reliability issues have come to light. Most manufacturers are unwilling to put anything potentially damaging to their reputations into print in any case - lest a customer might see it!   I needed a schem for the EV 2.0kW power amp a few year back and was offered a full manual for $20 from the local EV agents. When it arrived it was a joke. All the schematics were drawn without dots - you simply could not tell if any two lines that crossed at right angles were joined at that point or not !!   I rang to complain and was immediately told they are all like that - sorry.   The manual for the Crown PSA-2 amplifier has procedures for testing the amp after repairs have been done. The final test is for the VI limiter and involves driving each channel at 20V rms into a 1 ohm load. What the manual writer did not take into account is that if the VI limiter circuit *fails* to operate correctly, that channel will instantly blow up! Hell of a test - eh.   Manuals for many QSC amps ( USA series etc) give details on connecting an output transformer to convert the amps for 70V line operation. QSC even sell a 300W transformer for the job. But don't you dare do it !   The current limiting scheme QSC use is a real oddball and works only with resistive loads. Soon as a low or subsonic frequency comes along, the iron core in the output tranny saturates and instantly blows up the amp. One of my customers found out the hard way after and simultaneously destroying four brand new USA900s.   Over the years, I have had to evolve my own methods of safely bench testing amplifiers, before and after repairs, including non invasive setting of bias levels and checking VI limiters for correct operation into reactive dummy loads.   Far as I am concerned, Service Manuals are mainly for light entertainment reading.     .... Phil

ggherold@gmail.com: Dec 04 10:00AM -0800 On Monday, December 1, 2014 11:26:20 AM UTC-5, Don Kuenz wrote:   > ( \_/ ) > (='-'=) Don Kuenz > (")_(")   This is fun, http://www.dansdata.com/goop.htm   How about some vegemite? :^)   George H.

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