INS4004D in Pro-Log M900 PROM Programmer

Not to cause a run on Pro-Log PROM programmers, but the M900 at least has an INS4004D microprocessor (National Semiconductor 4004 second source) at its heart. I only found out because I'm trying to figure out why this M900 isn't working and opened it. I re-seated all the chips, hoping for a quick fix, but no go. Are there any known, simple to fix faults on these? It powers up, power supply is good, no output on the LEDs other than transient voltage spikes on startup causing individual elements to momentarily light. Otherwise, no activity. -- Sellam Ismail Vintage Computer Festival ------------------------------------------------------------------------------ International Man of Intrigue and Danger http://www.vintage.org [ Old computing resources for business || Buy/Sell/Trade Vintage Computers ] [ and academia at www.VintageTech.com || at http://marketplace.vintage.org ]