Problem with President Lincoln-please help

[KlondikeMike]

... When your car broke you just replace half of the car or diagnose failure first?

I agree with you ... if I was trouble-shooting a $50,000 car.

Not everyone is a smart as you (including me) and do not have the diagnosis capability or equipment to find the exact failed component in short order. Repeatedly. There will be another failed electrolytic just around the corner. Why only replace one failed capacitor? They are all past their expected lifetime and should be replaced.

[ch25]

I admire you. Without having equipment on the desk, diagnosis, measurement you know that all capacitor need to be replaced.
Do you know lottery numbers too?
Chris

[Buick Mackane]

I admire you. Without having equipment on the desk, diagnosis, measurement you know that all capacitor need to be replaced.
Do you know lottery numbers too?
Chris

Now now lemmy no need for cheek

[cro328]

When it turns on, it is always at the last frequency I used.
I totally agree with Chris, I wouldn’t change everything, but I would like to find fault.
I'll do the measurement as soon as I have time. I'm very busy with the job, but I make sure to report the result.
I know the easiest thing to do is replace the electrolyte, and what if it doesn't work well after the replacement.

Regards,Wally

[cb4ever104]

and what if it doesn't work well after the replacement.

Then you'll know it isn't an electrolytic. I agree that more testing and diagnostics are required. These types of intermittent faults can be a pain. Send it to a professional if you don't have time to do it yourself.

S

[Otter]

When it turns on, it is always at the last frequency I used.

Well, it's not the memory capacitor (1000uF 6.3V) on the CPU board then.

It's not likely to be any of the capacitors on the main board, although it you replace the 10V ones for the same capacity but a higher voltage, and you do it correctly, you will almost certainly save yourself problems in the future.

I would start with replacing C392 on the CPU board, as it is part of the reset circuit. C394 is another possible.

If your description of the fault is wrong, and it does Tx and Rx before the display comes up, replace C501 and C503 on the display PCB, and you might as well do C502 as well while you're there. I've had problems with them before, with display not coming up, but from the schematic I can't see how that happened.

Alternatively, send it to Black Spirit (Nick) and he'll sort it out for you.

[dt307]

remove all the glue and caps marked
check for bad traces
check the parts before you refit
seen this many many times esp under the regs and the blue cap traces been eaten away

if the radio does tx and rx with a blank screen forget looking on mainboard just pull the inter connections and refit

[cro328]

Thanks to the whole group who helped me solve the problem. Thank you for; Sammy ,Chris ,307 Chris ,the collector ,KlondikeMike ,26TM439 and Buick Mackane. I changed one 0.1uf 50v capacitor near IC313. I don't know the tag because it doesn't write on the board. I realized that my CPU board is not bord of lincoln but is the same as uniden 2830. After replacement, my president Lincoln immediately switches on.
Regards and sorry for my bad English.

cpu.jpg

Wally

[cb4ever104]

Glad you got it fixed , and thanks for sharing the details .

[dt307]

love a happy ending.......brings a tear to my eye

[KlondikeMike]

... Looks like a good time to order one of these, my electrolytic capacitor kit for this radio;

For those still looking, new link;
https://klondikemikescapkits.com/produc ... -kitdeluxe