We have a JBL VRX932LAP system with JBL VRX subs. the subs are ok. but the loud speakers are the issue the high frequencies drops flickering on and off between Left and Right speakers and it occurs at interval.
Please any help. Thanks
Are they going thermal? Are the amps switching on and off?
The amps are not switching on and off. I also noticed that the 2 bottom speakers on the right are louder the left bottom speakers and they are on the 0db switch. I replaced the cables cables and also change the outputs on the DBX drive rack 4800 that did not solve the problem. I have another 932lap at the side of the gallery which works well at loud music and drops during speech.
Our units began dropping highs intermittently as well as a customer's units. The fix that cured it is as follows:
1. Remove the amp module. Most VRX require removing the grille and woofer to unplug the cable on the back of the module, JBL left no slack for service. This is sucks when they are hanging in arrays. If this is the case with yours you can carefully wiggle the amp module until the connector pops loose. When you get it out you'll see that the cable is held tight by 2 tie wraps with eyes that are screwed into the box to hold a choke in place. You can carefully cut the tie wraps and get some slack in order to reconnect the cable without having to pull the woofer. If the array is permanently installed it should be fine like that, if you're using the boxes portable then I would reattach the choke with new tie wraps and screws leaving enough slack to allow connecting the amp module.
2. Remove the large sheet metal cover that covers the rear of the module. Then remove the small sheet metal cover over the input module (3 screws).
3. I recommend Deoxit D5 to clean the volume pot and the 2 HF switches. You'll need to get the straw close to the switch bodies mounted on the circuit board and work the switches as you spray them. On the volume pot you can see the contacts and get the straw right next to them. Work the pot and spray, if yours are like mine after 4 or 5 sprays I had a distinct change in the smoothness of the pot motion.
4. Let it dry well before reassembly and powering it back up.
5. No warranty expressed or implied, but this worked for us, hope it helps someone else.
We've been fighting this for a while and it's strange to me how few postings there are online about it. I tried to purchase the input modules from JBL and I don't think they would even sell them if I rememeber right, just the whole amp module. The VRX have served us well for many years and in the last couple of years have started having these issues. The disturbing thing is that the replacement amp modules I've gotten have seemed to exhibit the issue much faster than the originals did.