Do you have Hi-Line Nav? Then you'll want to read this! BM24 upgrade and repair info.
As a lot of HiLine Nav owners know, the standard system is very useful however lacks audio output power. The reason being the Philips tuner/amp module uses a very small TDA7375 amplifier IC - the maximum output of this amplifier is 4x 7w @ 10% THD (RMS will be significantly lower).
Here's the standard amp IC: http://i282.photobucket.com/albums/k...a.jpg~original The easiest upgrade to our systems is to fit the rather excellent Becker BM24 unit. This uses twin amplifier ICs to deliver 4x 47w @ 10% THD - a much higher output. It's not about pure power, however - the BM24 provides much more bass response thanks to it's higher power capacity. You really can tell the difference! Finally, a great feature (and a good reason to upgrade) is also the twin-tuners built into the BM24 - you get a continuously updating list of stations listed below the one you're currently listening to. Very handy as you can flick through the list with the control knob on the head unit, and press to select a station. Upgrading to a BM24 is very simple - you'll need to go into the spare wheel well, locate the Philips unit (on the right-hand side when looking into the boot) and remove it. The BM24 uses the same connectors as the Philips unit - so it really is plug and play. The only issue with the BM24 is the solder joints linking the power ICs to the main PCB fracture with vibration and age, meaning your unit may cut in and out (mine took about 5 minutes to power on, and then worked fine). Fixing this is simple - I've written a guide for doing this below. First, remove all Torx bolts visible on the outside of the unit, and remove the lid. http://i282.photobucket.com/albums/k...6.jpg~original Next, remove the PCB from the metal casing: http://i282.photobucket.com/albums/k...e.jpg~original Finally, reflow the joints circled below. They appear to be high-temperature solder - you'll need to get a fair bit of heat into them! Once you have the joint molten, add a little more solder to keep the joint firm. http://i282.photobucket.com/albums/k...6.jpg~original Re-assemble the unit and you're done! It should all work perfectly. :) |
Would the bm24 make a difference in audio if you have the hk amp fitted ?
|
Quote:
|
Quote:
|
Quote:
Worth a try, as the BM24 is certainly a very good improvement. |
Thanks for the guide. One question - I can solder wires together OK, so will I be able to solder the joints you mention without having done hardly any soldering on a PCB before (can't remember when I last did, maybe done it once or twice before) or do I need to be fairly experienced at soldering before attempting this? i.e. is it easy to mess up?
P.S. I went from Symphony non-HK to Highline BM24 with HK and it's miles better - even I could tell that despite knowing nothing about car audio! |
Great post Matty, thanks. I just picked a BM24 up on EBay for £65. A fairly decent price I think :)
|
Quote:
Quote:
|
I have BM24 just installed,and its live,screen on but wont tune-in any channels,could the cracking joints be responsible ?
|
Quote:
|
All times are GMT. The time now is 08:39. |
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright © 2006-2023, The Rover 75 & MG ZT Owners Club Ltd