27-06-2017, 02:05 PM
(This post was last modified: 27-06-2017, 02:06 PM by ppppenguin.)
I've woken up a power supply module. Probably didn't need to do it this gently but I used a bench supply to reform the main smoothers which were all OK. I changed a 1000uF 6V Callins which was likely to be faulty. Also changed the BFY50 and a nearby electrolytic which had suffered mechanical damage. I reckoned it was worth changing the beam limiter preset as the original skeleton part was filthy and likely to be scratchy if not worse.
I also used a PSU to check the 30V zener shunt stabilisers which were both fine, as were their associated Mullard "blue" electrolytics.
Repalced module, switched on. No smoke.
Time to look at a regulator panel. I have a choice of 2. Both look reasonbly OK but with minor mechanical damage. The spare has been a bit damp at some point, has minor corrosion and has more mech damage. The original one is clearly better looking so that's the one I'll go for. I'll replace the odd fractured wire, check out the 3 series pass devices and investigate a resistor that's clearly overheated. Just 1 Callins cap which will be changed. The 3 presets will get some Servisol as a pre-emptive measure.
I also used a PSU to check the 30V zener shunt stabilisers which were both fine, as were their associated Mullard "blue" electrolytics.
Repalced module, switched on. No smoke.
Time to look at a regulator panel. I have a choice of 2. Both look reasonbly OK but with minor mechanical damage. The spare has been a bit damp at some point, has minor corrosion and has more mech damage. The original one is clearly better looking so that's the one I'll go for. I'll replace the odd fractured wire, check out the 3 series pass devices and investigate a resistor that's clearly overheated. Just 1 Callins cap which will be changed. The 3 presets will get some Servisol as a pre-emptive measure.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
