[time-nuts] Repair of PRS10 Lamp Assembly

["Dr. Götz Romahn"]

dear all,
beeing a silent reader of this list for a while, I now ask my first 
question.
I have obtained a PRS10 that was declared faulty and it is. The problem 
I located in lamp assy.
Lamp ignites only after warming up and pushing by a voltage kick from 
abt. 24V to abt 28V on the -24_heat line for some seconds. PRS10 gets 
locked there after and rbmon shows a seemingly healthy unit (see 
attachment). But... within some 15 to 45 minutes later light from lamp 
degrades as seen through "LAMP VIEW" hole in top board as well as AD9 
Photocell I/V going down from 1.68 after ignition to 0.158 and lock is 
lost of course. Since all heating and voltage diagnostics do stay within 
accepted limits I suspect some problem within lamp enclosure (see 
attachment). Your help for further diagnosis and any hints for obtaining 
spare parts would be appreciated very much.
Cheers Goetz
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