Working on old PL3000 pre with switching issues. Powers up defaulting to Tuner input correctly. When I switch to another high level input it will switch LED to new in put but the tuner LED stays on also. Doesn't do this every time but at random. See that the relays are no longer available. Uses relay that matches 16pin DIP footprint. Looking for same footprint that matches on small signal relay. Not finding. Service manual talks about a relay regulator circuit but can't find info on that. HELP!
The entire circuit works off the pair of 3 pin 20V regulators.
There are many pcb mount relays (Omron, etc.) that will substitute, just match the type and footprint.
PHASE-LINEAR 3000 SERIES SM Service Manual download, schematics, eeprom, repair info for electronics experts
There are many pcb mount relays (Omron, etc.) that will substitute, just match the type and footprint.
PHASE-LINEAR 3000 SERIES SM Service Manual download, schematics, eeprom, repair info for electronics experts
The problem you described when you switch to another high level input is most likely due to the fact that even a few meg ohms of resistance can cause the CMOS IC's to falsely trigger. I would suggest spraying some lubricant/ cleaner into each one of the micro switches.
The original clear see-through top relays Phase Linear used also had problems. The originals were HB2-DC24V relays. The replacements were yellow-topped nitrogen gas filled sealed relays with gold contacts and the part number was HB2E-24V. They are available on ebay.
Early 3000's had (13) relays in them. Later 3000's added a 14th relay in the tape buffer circuit to prevent 3-headed tape decks from feeding back.
NOTE: Early on in production, Phase Linear replaced 1/2 of the 13 relays with the HB2E-DC24 relays. Eventually replacing them all with the HB2E-DC24V's.
You can also sent me a message for further information.