- Seeking Opinon on EPROM Problems - 5 Updates
- Dumont 1062 scope - 4 Updates
| jurb6006@gmail.com: Jan 07 09:32PM -0800 I have a bunch of the same units now that I kinda work for factory service. These are Karaoke machines which are modified CD/DVD players. I get like three different symptoms on certain models. OK there was a fourth that was even weirder but that was only one out of a bunch. Also, out of a bag of EPROMs they have the same symptoms. We got alot of parts that are used and that is something totally else to deal with. Anyway, when you find there are only three major symptom sets that follow these EPROMs around (I spent the better part of a day switching them to numerous mainboards)Would you think the EPROMs went defective or they got hit with a software error, like having the plug pulled at the wrong time ? These things DO have mechanical power switches. But then this is a Chinese manufacturer and they might have gotten a batch of them really cheap and they ARE the problem. To exacerbate this dilemma, these things are shipped in worldwide. Shipping costs money. But if I order a shitload of ICs and the same thing happens that is worse. If it is a software thing, I got the EPROM copier and if it is likely to be software I need zero parts. Just put in a chip with a the good data and bam it is done. How long it lasts depends on alot of things, cosmic rays n shit. (I shit you not, there are articles on that, in fact should I put a foil tape on top ?) And what if I get cheap EPROMs and they go bad ? Well, that's the question. Start flashing the chips I got or get new ones ? Note that we also got rush jobs. Not really rush but they have been there long enough. |
| whit3rd <whit3rd@gmail.com>: Jan 07 11:26PM -0800 > I have a bunch of the same units now that I kinda work for factory service. These are Karaoke machines which are modified CD/DVD players. > I get like three different symptoms on certain models. OK there was a fourth that was even weirder but that was only one out of a bunch. Also, out of a bag of EPROMs they have the same symptoms. We got alot of parts that are used and that is something totally else to deal with. > Anyway, when you find there are only three major symptom sets that follow these EPROMs around (I spent the better part of a day switching them... Well, if the EPROMs were really in a bag... that usually isn't proper storage. Read and generate checksums for the EPROMs; if the checksum is wrong, different from others with the same version label, that's a bad part. I wouldn't waste time erasing/reburning old parts (are they UV EPROMs, or flash, or EEPROM?), I'd just program a flash replacement. The parts are cheap enough, and 'the better part of a day' is not. Of course, generate a checksum after burning, verify that before using the part. |
| mike <ham789@netzero.net>: Jan 08 02:51AM -0800 > If it is a software thing, I got the EPROM copier and if it is likely to be software I need zero parts. Just put in a chip with a the good data and bam it is done. How long it lasts depends on alot of things, cosmic rays n shit. (I shit you not, there are articles on that, in fact should I put a foil tape on top ?) > And what if I get cheap EPROMs and they go bad ? > Well, that's the question. Start flashing the chips I got or get new ones ? Note that we also got rush jobs. Not really rush but they have been there long enough. One symptom that EPROMS can exhibit is speed related. You can test them all day in an EPROM programmer, but they still won't work in the product. This was a problem in some early Compaq 386 laptops. And some TEK instruments. Reading the device in the programmer, then writing it back fixed 'em. The laptop ones failed again eventually. As I recall, the designers let some of the control lines on the prom float. I guess that allowed some electrons thru to contaminate the bits. New chips soon exhibited the same symptom. |
| John-Del <ohger1s@aol.com>: Jan 08 04:26AM -0800 > If it is a software thing, I got the EPROM copier and if it is likely to be software I need zero parts. Just put in a chip with a the good data and bam it is done. How long it lasts depends on alot of things, cosmic rays n shit. (I shit you not, there are articles on that, in fact should I put a foil tape on top ?) > And what if I get cheap EPROMs and they go bad ? > Well, that's the question. Start flashing the chips I got or get new ones ? Note that we also got rush jobs. Not really rush but they have been there long enough. Most of what I see are the 25 series eeproms that Chinese and Black Friday TVs come with and they do corrupt. They also will sometimes suffer eeprom hard failures. Many times, I can pull the eeprom and copy it (assigning it a file name that denotes it's questionable status) and write it right back restoring normal function. When this works, I change the file name to indicate it's a good .bin file. Other times, I can copy the file but need to program a new blank for it to work. Most of the times though, I can't get a good file from the old eeprom (simply corrupted) and need a good file. Of course, manufacturers won't supply the .bin file but any TV I get in for repair gets it's eeprom pulled and copied regardless of what it's in for. If I'm forced to buy an eeprom or a main board I pull that eeprom and copy the file to my computer so I won't have to buy another one. Eeproms are cheap. Typically you can get 10 of any given number for less than $10 including postage from China. |
| Pat <pat@nospam.us>: Jan 08 10:06AM -0500 >> If it is a software thing, I got the EPROM copier and if it is likely to be software I need zero parts. Just put in a chip with a the good data and bam it is done. How long it lasts depends on alot of things, cosmic rays n shit. (I shit you not, there are articles on that, in fact should I put a foil tape on top ?) >> And what if I get cheap EPROMs and they go bad ? >> Well, that's the question. Start flashing the chips I got or get new ones ? Note that we also got rush jobs. Not really rush but they have been there long enough. I am not familiar with the machines you are repairing, but I might be able to help you have your questions better understood. EPROMs are erasable programmable read only memory. They are erased by shining UV light in that little window. The cover keeps stray UV light out - NOT "cosmic rays and shit". One thing to keep in mind is you MUST erase them before reprogramming them. Later parts were EEPROMS. EE stands for Electrically Erasable. Those don't have the little windows. You don't Flash PROMS, EPROMS, or EEPROMS. You program them. Modern technology uses none of the above. Instead, a completely different technology called flash is used. So, when you flash something, you are updating the flash memory in the device - not an EPROM. Best of luck with your repairs. |
| legg <legg@nospam.magma.ca>: Jan 07 12:35PM -0500 >> Anyway I was playing with it over the holidays and it seems to be reading vertically on the screen instead of horizontally like a normal scope. Anyone ever heard of or seen that before? Any ideas? >Just because you have something to say doesn't mean you should reply to a >17 year old thread, even if it was resurrected last year. With usenet being what it is, there are posts being recycled with new dates as people shift servers.........perhaps they think they're doing you a favor. Unless you read the headers, it's not always obvious. I'm seeing my old posts showing up from as far back as Y2K, with new poster names and date. RL |
| Kaz Kylheku <kaz@kylheku.com>: Jan 07 07:20PM >> Looks really cool and the thing weighs like 100 lbs. > Just because you have something to say doesn't mean you should reply to a > 17 year old thread, even if it was resurrected last year. That doesn't matter at all because the posting doesn't quote any of that article. The only clue that it's a followup is the References: header and the "Re: " prefix in the subject line. Take away those, and you would have no clue it's a follow-up to anything old. |
| jurb6006@gmail.com: Jan 07 09:52PM -0800 >17 year old thread, even if it was resurrected last year. >If you have something to say, say it, don't reply to a really old >post. >This was isn't even the same model as someone was asking about >before. " I totally agree. Google should show this tip when people get on it to access Usenet. Reason ? Others might have to wade through hundreds of posts to get to the meat of things. And as you said, the thread title does not even mention the necromancer's model number. How is anyone else going to find it ? I hope all the Googlesters read this and get with it but they won't. Even if they do, more will come. Actually I was here for the OP, but under a different domain and did not comment. Actually some old scopes did have a switch to interpolate X with Y. Rare, but I saw them. You could also do that with a bunch of Teks that used plugins, I have done it on the 7000 series just for fun. Anyway, in this case I think there is no horizontal sweep and seeing the vertical witho9ut that gives the impression it is turned. Really, how the hell would that happen ? The way to tell is with the position controls. What happens when you turn those ? |
| Kaz Kylheku <kaz@kylheku.com>: Jan 08 02:53PM >>If you have something to say, say it, don't reply to a really old >post. >>This was isn't even the same model as someone was asking about >before. " > I totally agree. Google should show ... ... a big disclaimer saying "... please, please, make every possible effort to use a real newsreader connected to an NNTP server and use this garbage service only in some sort of emergency." |
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