Instruction/ maintenance manual of the product ISA 750 QSC Audio
Go to page of 4
1 ISA0001 T itle: ISA T urn-on Hangup Bulletin #: ISA0001 Issue Date: April 4, 200 2 Models Affected: ISA 750, 800T , 450, & 500T Bulletin Revision: A Production Range: 01/2000–04/2002 (serial #.
2 ISA0001 • Desoldering equipment or solder braid • Four 4.7-volt ¼ -watt zener diodes (Microsemi DZ840731ET/R; QSC part number QD-0004.7-ZT) T est equipment required: • Oscilloscope • 2-ohm resistive load (rated for at least 1200 watts) • Wire or other means of shorting the amplifier output • V ariable AC transformer (e.
3 ISA0001 unsolder and remove it. Install and solder a new zener diode oriented in the same direction. Do the same with diode D210. 1 1. Check your work. Don ’ t reattach the channel module assembly and heat sink to the chassis yet. Instead, continue with the bias and current-limit calibration.
4 ISA0001 and wait until it cools down to about room temperature. 6 . Measure the DC voltage across R147. Adjust bias trimpot R131 to reach the correct voltage shown in T able 1. 7 . Next, measure the DC voltage across R247. Adjust bias trimpot R231 to reach the correct voltage shown in T able 1.
An important point after buying a device QSC Audio ISA 750 (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought QSC Audio ISA 750 yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data QSC Audio ISA 750 - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, QSC Audio ISA 750 you will learn all the available features of the product, as well as information on its operation. The information that you get QSC Audio ISA 750 will certainly help you make a decision on the purchase.
If you already are a holder of QSC Audio ISA 750, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime QSC Audio ISA 750.
However, one of the most important roles played by the user manual is to help in solving problems with QSC Audio ISA 750. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device QSC Audio ISA 750 along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
