- Peavey XR684 mixer amp - 5 Updates
- hopefully easy electronics question - 3 Updates
- Advice requested Whirlpool Duet Sport Washing Machine "popped" - 1 Update
| "Gareth Magennis" <soundserviceleeds@outlook.com>: Jun 22 06:58PM +0100 "N_Cook" wrote in message news:nke4tc$ro5$1@dont-email.me... With just the main PA rail AC supply connected, no load,sometimes at switch on will draw sustained >2 amp , so quickly switched off. At 50% mains , sustained 1 amp draw until switched off. Mains Tx ok on its own. DVM-D cold testing of PA devices and bridge rect etc check out reasonable. What to look for cold initially? I may try hot test again with the speaker output pcb disconnected as speaker protector thtristors on there. Initially one output channel failed soon after power up, which could be sp prot failure presumably, mains fuse did not blow though but that >=500W would be going somewhere it shouldn't. Perhaps another 50% mains half second try out and see if a thyristor is hot. Peavey typically put a Triac circuit on the speaker outputs to short and blow the amp/fuses instead of the speakers should it go DC. I tend to use a dual bench current limited supply, and remove the Triac when troubleshooting. Mine only goes to +-30v, but I've never found that a problem, it will still safely find a short etc. Gareth. |
| N_Cook <diverse@tcp.co.uk>: Jun 22 07:37PM +0100 On 22/06/2016 18:58, Gareth Magennis wrote: > Mine only goes to +-30v, but I've never found that a problem, it will > still safely find a short etc. > Gareth. What seems odd about this , is it is intermittant. Sometimes it would power up properly , even at 100% mains, ie nothing is permanently defunct. I'll have a closer look at solder joints, if a bias is dropping out. |
| N_Cook <diverse@tcp.co.uk>: Jun 23 12:36PM +0100 All very odd. One of the crowbars is doing what it should do and heating up a couple of degrees in the process. Randomly about 1 in 5 times at switch on, this crowbar conducts and drops about .9V as a rail voltage is going on that speaker line. Oddly , at 50% mains, whatever is wrong , will drop out after 1 or 2 seconds returning mains draw to normal. One of the output devices failing internally and correcting/"breaker" going-o/c from current passing ? With the heatsinks off and manually switching off the amp, IR thermometer should show which, the next time of powering up. There are bad design/assembly errors in this amp. Firstly what does not at the moment seem to be the problem, TO220 pre-drivers , the legs have shoulders so can normal assembly take advantage of thru-board anchoring of the pins , when soldered. But there is 3mm or so of freeboard under the shoulders and 2 of the 4 such devices are waggling loose , flexing the pcb traces with any movement/vibration of amp. The 4 h/s screws per h/s have no spring washers under the heads, so the polyester of the pcb compresses with age and heat (1998 make), one of the screws was not very tight, I suspect the precursor problem. . |
| Phil Allison <pallison49@gmail.com>: Jun 23 05:32AM -0700 Gareth Magennis wrote: > blow the amp/fuses instead of the speakers should it go DC. > I tend to use a dual bench current limited supply, and remove the Triac when > troubleshooting. ** The Kook needs to disconnect the relevant triac crow bar and see if that fixes the problem - could be that it is being triggered by a switch on thump. Also check the ESR and uFs of the electros in the trigger circuits - if any have lost capacity, triggering becomes more sensitive to large LF signals. ... Phil |
| N_Cook <diverse@tcp.co.uk>: Jun 23 02:47PM +0100 For the following designations I'm using PV "XR power amp" schematic as only preA seems available for the XR684 Two base connected o/p 2SA1302 ,only, of the R ch are heating up for a second,driven from Q213(E) . At this stage don't know if an internal problem to one of those pair , or as quite accurate "timing" of excursion, I'll put a monitor on Q213{B} as its probably a further back excursion in the splitting area , involving a cap perhaps to give the timing. Enough for today |
| ehf0528@gmail.com: Jun 22 06:22PM -0700 On Thursday, August 15, 2002 at 12:30:56 AM UTC-4, Stephen Jacobs wrote: > system working by replacing these capacitors? > Thanks for any help, > Steve I am so sorry if I am sounding like a complete novice in this, but I AM ONE! Rather than learn about circuits, schematics, chips, soldering, troubleshooting, etc., does anyone know of any person or shop that troubleshoots and fixes these Atari 5200 (especially 4-port model) machines? I just had my first major fail at this tonight and it is quite disappointing and disheartening. I'm 64, unemployed, and disabled, and am quite willing to learn anything new, especially electronics, but perhaps I have bitten off more than I can chew with having about 13-15 4-port 5200s that don't work for one reason or another. I thought I could make one good console out of 2 bad ones, but it's not working out that way for me. The only option is to try to get them fixed. Some of you on this board make it sound so EASY..."just pop out this chip, swap it with this chip, if it works then you have found your culprit", etc. But for most of us here, this is total "greek to us". Can someone please point me and others with me in the right direction? I'd even be willing to pay to have these machines repaired (if within reason), it sounds like some of you could do it in under an hour for each console. I've almost mastered refurbishing the OEM CX-52 controllers with new parts...that's mostly just mechanical, replace the old, put in the new, put it back together carefully and hope it works! But please, someone come to my aid and reply to me. Do repair people/shops even exist for Atari 4-port consoles? Thanks so much for your kindness in even reading this far. - Ed Fernandez, South Amboy, NJ - June 22, 2016 |
| Allodoxaphobia <knock_yourself_out@example.net>: Jun 23 02:30AM > On Thursday, August 15, 2002 at 12:30:56 AM UTC-4, Stephen Jacobs wrote: >> I have an Atari 5200 videogame system. The motherboard is dated (c)1982, <snip> > I am so sorry if I am sounding like a complete novice in this, but I > AM ONE! ...in several ways. Why _the hell_ did you reply to a FOURTEEN-YEAR OLD posting instead of starting a new one to request help for your problem(s)? sheeesh!! google groopers!! |
| Rheilly Phoull <rheilly@bigslong.com>: Jun 23 03:48PM +0800 On 23/06/2016 10:30 AM, Allodoxaphobia wrote: > Why _the hell_ did you reply to a FOURTEEN-YEAR OLD posting instead > of starting a new one to request help for your problem(s)? > sheeesh!! google groopers!! Well disregarding other "helpful" comments :-) it would seem you havent googled "repair atari 5200" ?? Theres a heap of posts on that one !! |
| Diesel <me@privacy.net>: Jun 22 08:41PM Danny DiAmico <dannydiamico@yahoo.com> news:ngm06g$6r0$1 @news.mixmin.net Sun, 08 May 2016 00:10:57 GMT in alt.home.repair, wrote: >> broke it? <g> Map the laundromats? > I think the multiple power surges during the recent rain is what > fried the MMU board. Multiple surges, depending on duration and surge strength can take their toll on any surge surpressor too. Including the panel install style. The panel surge surpressor does offer some protection, but, don't put all your eggs in one basket. -- MID: <nb7u27$crn$1@boaterdave.dont-email.me> Hmmm. I most certainly don't understand how I can access a copy of a zip file but then not be able to unzip it so I can watch it. That seems VERY clever! http://al.howardknight.net/msgid.cgi?ID=145716711400 |
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