View Single Post
  #4   Report Post  
Posted to sci.electronics.repair
John-Del John-Del is offline
external usenet poster
 
Posts: 263
Default Seeking Opinon on EPROM Problems

On Friday, January 8, 2016 at 12:32:43 AM UTC-5, wrote:
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 ****load 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 ****. (I **** 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.