M7310 transmit volume, Schematic?

[byacey]

I have a number of M7310 and '08 sets that have low transmit volume. Replacing the handsets and cords doesn't seem to help. Doea anyone have a schematic or a partial schematic showing the input stage for these sets? I suspect something has deteriorated in the preamp stage. This is on an old DR5, and it doesn't seem to be port specific; The problem follows the phone, no matter what extension port being used.

 

[wip]

Sounds like its time to update the KSU to a newer Cabinet style and release of software, Newest version is ICS 7.0 in either a Compact or Modular format depending on the number of sets you will nee dto equip.

wip

 

[byacey]

I know this is an older KSU, but some of the phones work well on any port. In fact I have swapped KSU's and the problem still exists with particular phones, so I believe this to be a problem with the specific phone sets.

 

[simoslammer]

Have a look at the line cord socket on the bottom of the phone. If this socket is white then you will have a potential fault with leaking capacitors. At times the phones can be repaired by changing the caps and giving the pcb a clean. I find on most occasions the phone is no good and needs replacing.

If this happens on all phones on the system. Is it on all calls or just external calls. On external calls I have seen this happen. The problem has been the dreaded leaky caps on the lines of the compact 616 system.

Never seen this fault on any other systems.

Hope this helps.

 

[TRONIC1]

I'm with simoslammer on this, the older style 7000 series sets (the sockets are usually low horizontal) have this problem. If you replace those sets with sockets that are high horizontal or vertical this will probably fix the problem.

I'd rather have a bottle in front of me than to have a frontal lobotomy

 

[byacey]

When you are talking leaky caps, you are talking about the few electrolytics that I see; is that right? If that's the case, I'll try swapping them out.