I thought I'd have a look, and I'm getting 8.1v at the input and 7.3v at the output of U21, so the 12v section does appear to be broken. Caps are philips -- how can I tell a dead cap? It's not bulging or oozing or anything, but I guess the 12v section being broken is a good indication this cap is defective?
It is good indication for the TR2 are dead. If TR2 replaced and again no 12V, the cap is defective
then the new TR2 killed...
Removed capacitor can be checked capacitance meter.
My experience are: the Philips capacitors, especially in arabic machines (which are in hot Egypt for a many long years) are dried out. I measured about half capacity on a removed defective C9.
It is good idea replace all Philips capacitors, but only the C9 looks a critical which can made not working machine.
I checked
the another type capacitors also from arabic machines: not found capacity loss.
Also, the modulator seems like it may have been bodged. There's a cap and resistor soldered together in what looks like a retrofit, but it may well be like that on all EP's, I've not taken the other one apart in a while. Also there is a wire not connected to anything on the underside of the modulator! Pictures attached.
I guess somebody tried repair the machine and thought the problem with the modulator.
High res photos of ISSUE 5 board, you can see how originaly placed the components at the modulator:
TopBottomAnd on a different problem, the 6 key is sticking on my other EP64 -- looks like the keyboard membrane has died. Good thing you can get new ones on eBay, although they are expensive...
The keys in one row or column? If yes the it is a typicaly sign of the connector tail of the membrane are broken. Usualy at the motherboard connection. Cut the broken few milimeters and will work again.
But it is can break again due the age. After few cuts the length not enought. then needed the new membrane.
