As most of you knows about my EX Crown's 5000VZ that I owned, I have modified SPI-IOC led from green wich shows SPI signal and brighter green who shows IOC error (clipping) with bicolor led with common cathode green (SPI) and RED (IOC).

Originall acting:

https://www.youtube.com/watch?v=I2iPgeGvArU

Modified acting (observe on middle led (SPI+IOC):

https://www.youtube.com/watch?v=tO_26jekWUw

Here's the modification (made just for one channel in picture just to observe differences), all owners of crown 5000-5002VZ must modify channel 2 too as I have modified Ch 1 in attached picture.

Cheers mates!

https://postimg.cc/FYmwJ1wh" rel="nofollow">

Thx!!!!!!!👏👏👏👏👏👏👏👏👏

If limiter on back side of the amp is not used (OFF), none speaker can survive if 5000 VZ is in hard clipping

One of them could be directly soldered on PCB with no socket for fast replacing (so, I recommend to cut it each pins of integrated circuit with nailclipper or scissor pliers and desolder each pin separately, one by one as very tiny cooper traces, can be exfoiled.

Also replace U500 and U501 (thermal sensor LM334) wich are located on output devices heatsinks.

Check also Base and Emmiter pins of output devices to be good soldered on PCB, because most of them can be with small cracks, bad solders (and bad contact), or corrrosion (as in next pictures), where U can find/locate also, thermal sensor (in the midle of PCB of output devices heatsink). 

https://postimg.cc/nj9yS9d9" rel="nofollow - https://postimg.cc/nj9yS9d9

https://postimg.cc/S2M2xjvW" rel="nofollow - https://postimg.cc/S2M2xjvW

Of course, it must be changed all of above for both channels!

Good luck!

I'm in trouble with channel 1 of my 5000vz. 

IOC led lights brigth when signal is over -10 dbu from mixer output. 

the sound out of the speaker seems to be ok. 

So Where do you think the problem is located?

Thank you

Lorenzo

Hi. 

First I need answer to a simple question: this pressumed fault was happened recently, or this is the way that amp behaves?

So: rotate both volume knobs to maximum clockwise, load amp with 8 or 4 ohms each ch, prefferably identical subwoofers. Insert mono ballanced signal to both channels using one Y adapter, and give it some signal.

Watch IOC led's, both must go to bright light in the same time for both channels when amp output is as max output capacity or distortion are greater than 0.05%.

Thell me how it is the result of this test, if one ch is go brighter led too earlier than other, or boths act almost the same.

Then we go further.

Thank you for fast reply, really appreciate. 

The fault was happened recently. 

I've already done the test with 2 identical subwoofers, mono signal and a Y-adapter cable on both input. 

The result is that only on channel-1 the IOC LED becomes brighter much earlier than other. 

Check in front of amp under air filters are 2 switches as in picture. With amp turned OFF, move all two switches couple times from left to right and vice versa to pass on all 4 positions (could have a bad contact), and asssure after this trick to be both in VZ ODEP mode.

https://postimg.cc/k6yYDmyD" rel="nofollow - https://postimg.cc/k6yYDmyD

After doing that, repeat the test described in my upper post and see if all is OK. If is the same (one ch is going brighter early than other), it looks to be a fault on VZ stage on that channel wich bright IOC led, early.

For that, amp needed advanced repair.

If you can, U must replace U703 circuit (NE555, LM555) for CH1, maybe this will solve problem. 

If not, try to replace U702 too (LM393).

And if not, the last one wich could be needed to be replaced is U705 (LM339).

https://postimg.cc/0bLCRmqD" rel="nofollow - https://postimg.cc/0bLCRmqD

I recommend to cut it each pins of integrated circuit with nailclipper or scissor pliers and desolder each pin separately, one by one as very tiny cooper traces, can be exfoiled!

Wait for news (good ones I hope), after doing what I said!