Extreme electronics repair

A short tale of taking extreme measures to try to fix electronic gear. "N_Cook" oughta especially appreciate this.

So I found this receiver in the dumpster where I live--Aiwa "home-entertainment"-type of unit, meaning probably medium-fi for people whose idea of good sound is lots of thumping bass: has presets for "dance", "rock", "pop", "hall", "arena", etc., etc.

Plugged it in and the display lit up with "AM 12:00", but no response from any controls. OK, time to open it up.

Inside, everything--every circuit board and component--was covered with a fine light-brown powder, with a couple of leaves here and there. Evidently, the whole thing had been submerged in muddy water at some point.

Hmmm, what to do? Got $0.00 in it so far. So I did the only reasonable thing: drug it outside, hooked up the hose, and sprayed it liberally with clear water. Got all the mud out, so far as I could tell.

I took it inside, let it dry for 2 days. Today, I powered it up, and whaddya know? It responded to the "power/standby" switch. Heard the relay click and everything. Responded to every function. Even the tuner appeared to work.

Of course, the downside is that the damn thing doesn't work. No sound; obviously some serious problems there somewhere. And the tuner wouldn't lock onto any signals. But I was surprised that so much of it functioned normally. I expected the display to be toast, or the logic completely blown.

So I'm just sayin', if you ever encounter a piece of equipment that's been in a flood, and if you need to get at least part of it working for some reason, you could try this method.

At this point, it's not worth my time or effort to attempt any further repairs on this unit. But at least it was fun.

Give it more time. Set it out in the sun.

greg

I used to do that with arcade game logic boards. I'd buy them off operators (they were older boards that were removed when the game was converted into a newer game) by the pile. The ones that were really grubby I'd take outside with a bucket of soapy water and a scrub brush and clean 'em up. Rinse off with the hose and let 'em sit out in the sun all day to dry off. I've even heard of guys putting them in a dishwasher with the heated dry cycle off.

I remember in 1969, was working at DEC in the the data communication/ display department. One other fellow was assigned a new crt display forerunner of the computer monitor. Any way, he had trouble with some boards and you would be seeing him in the mens room washing off boards. They worked better then than whatever he was using. We usually used a trichlorethelene spigot to clean boards.

greg

On 4/1/2009 9:45 AM snipped-for-privacy@techie.com spake thus:

You left out the part where you said "... and they worked fine after this."

Or did they?

."

Why wouldn't they? The ones that didn't need repair to begin with fired right up and as far as I know are still operate to this day.

Snip

!n the 40's D&RG rail road used car radios in their private cars. The soot from coal fired engines was so bad I could not read the parts. Dunked entire radio chassis in a 5 gallon bucket of carbon tetrachloride. They came out spotless. Dried quick. Never seemed to hurt any thing. Also on home radios used carbon tetrachloride in a squirt can to kill cockroaches before removing the back covers. WW

On 4/3/2009 6:20 AM snipped-for-privacy@techie.com spake thus:

Because soap and water can damage electronic components?

OK, but you didn't say that, so I wouldn't have assumed that.

Not likely. The most chance for damage is if you pwr up the pcb without drying it out *all the way*. Now taking a transformer to the car wash I'd be hesitant to do.

Not likely. The most chance for damage is if you pwr up the pcb without drying it out *all the way*. Now taking a transformer to the car wash I'd be hesitant to do.>>

Perform the normal cleaning and quality control procedures that the factory would use in manufacture or re-manufacture.

I could tell you what those are but it would violate confidentiality and shock the heck out of you all.

On 4/3/2009 10:15 AM WW spake thus:

Ah, yes, the Good Old Days, when men were men and nasty carcinogenic chemicals were freely used ...

Hi!

It's a good start. But now you need to figure out why there is no sound if you want the "extreme" title or close to. :-) Your odds of getting it back to 100% are very good if it was without power when this calamity struck.

I had a massive flood in my own basement back in 2004, where I had my entire computer "lab". Well, two things that were down there had notable stories behind their recovery. The first was a PS/2 Model 85, which for various (mostly sentimental) reasons, I was not going to let go...at least not easily.

I started by throwing the whole mess into the dishwasher, just to get the muck off the boards. And then I slapped it together on the kitchen table:

You can see the level of muck by looking at the power supply I had to use for the initial test. This machine is still running to this day.

But the big one was the HP OfficeJet 500. I wasn't going to repair it, I really wasn't. It had suffered badly and the only promising thing it did after the most cursory of examinations was to power on. It was Not Happy. I used it as a fax machine, because it had two invaluable features--all the faxes could go to the PC for later perusal (and trashing of the obvious garbage) and it supported distinctive ringing service. I needed both of these features.

Windows 2000 and XP don't support distinctive ringing. The multifunction devices I found to try and replace the OfficeJet all treated faxing as though it were only a last minute add-on. Not *one* could save a fax to the computer without printing it, and I tried a lot of them.

So I went back to the OfficeJet 500, still sitting in a sad looking pile on the floor, where I had placed it. I dragged it up to the kitchen table and lit into it, pulling off plastic trim, cleaning muck out of everything. I repaired the phone line circuitry (fried by being underwater) with a second unit as a known working reference. It took at least two hours to get it all cleaned out. Finally it was time for the test.

Keep in mind that the unit had been underwater for several days, without power for months and was not at all happy when I powered it up after letting it dry out.

With a new ink cartridge in place and all the muck cleaned out, the unit came right back to life and printed out three faxes it had received before going under. Astounded wasn't the word.

That was five years ago. It's still going to this day.

William

Back when all Tektronix 'scopes weighed a ton and used nothing but tubes, the first thing that happened when one got sent in for repair was that the side panels got popped off and the whole thing got a good dunk-and-slosh in hot soapy water, followed by a rinse and a trip through the hot air drying oven.

Only then did a tech take a look at it.

Isaac

This is especially useful for grungy remote controls. You know, like the one that was never the same after the kid dropped it in his Coke, or whatever. I've fixed several by taking them apart, scrubbing all the pieces with soap and water, and blowing them dry with compressed air. Good as new. Fortunately most of the stuff people spill on remotes is water soluble. ;)

Easy fix but the pads are usually too worn to bother with by the time you get around to it. I wish there was at least a 6 mo solution to that problem. Sometimes only the original will do for higher functions.