Transceiver is locked on Channel 1. Up/down buttons and channel knob have no effect.

Here you go

OWNER'S MANUAL midlandusa.com - Midland Radio

https://midlandusa.com > uploads > 2016/12 > 75-...

PDF Midland 75-785. 40 CH AM HANDHELD CB TRANSCEIVER. 78-785 is a 40 channel Citizen Band Mobile operation, that is big on performance.
15 pages

HANDHELD CB RADIO - Midland Radio

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PDF Sep. 10, 2012 - Midland 75-785. 40 CH AM HANDHELD CB TRANSCEIVER. 78-785 represents state-of-the-art high-tech engineering. Designed for 40 channel Citizen ...
8 pages

Midland 75-785 Owner's Manual - ManualsLib

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View and Download Midland 75-785 owner's manual online. ... DC 13.8V CHARGE 40 CHANNEL CB TRANSCEIVER 75-785 SQUELCH VOLUME DC 13.8V CHARGE page 4.

75822 HANDHELD CB TRANSCEIVER User Manual G-300 ...

https://fccid.io > Midland Radio Corporation > 75822

75822 HANDHELD CB TRANSCEIVER User Manual G-300 owners guide Midland Radio ... Owner's Manual Model Number 75-822 Features Include: 40 CB Channels 10 ...

USER MANUAL Midland 75-822 40-Channel 2-in-1 CB Radio

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User manual, Midland 75-822 40-Channel 2-in-1 CB Radio, Midland, 75-822, 40-Channel, 2-in-1, CB, Radio, with, Weather, Alerts.

SETTING
To change the operating frequency of a channel:
1 With the transceiver power OFF, press and hold the PTT
switch and Up key while turning the transceiver power ON.
•
Continue to hold the Power switch, PTT switch, and Up
key until the LED indicator lights yellow and the transceiver
announces "Self".
2 Release the Power switch, PTT switch and Up key.
•
The transceiver announces "Channel Number".
3 Press the Up/Down key to select your desired channel, then
press the PTT switch to con? rm the selected channel.
•
Upon releasing the PTT switch, a beep will sound and the
transceiver announces "Table Zero".
4 Press the Up/Down key to increment/ decrement the Table
number, to select the new channel frequency.
•
Press and hold the Up/Down key to continuously increment/
decrement the number.
•
Table numbers and their corresponding operating frequencies
are provided in the tables on pages 13 and 14.
•
A voice announcement will inform you of the selected Table number.

if a reset has failed, these means either the eprom or the cpu is damaged.

Great news, I'm happy you've got the solution to your query.

cheers,
Peter

View videos on YouTube regarding "mixer setup". Find the parts of setting up of "effects". Don't worry that you have a different mixer, the principles are all the same for analog mixers. Steps are this: Set the EFX send level for EACH of the input channels (knob above each channel gain) for the proportion you want for each channel. Check that the level you are sending does NOT cause the effect clip light to light very much. Set the effect you want, delay, echo, etc. with the selector knob. Advance the output sent to the power amp with the two knobs in the upper right of the panel. Adjust the "time" knob for the delay or effect depth you want. Then go over the same settings in the same order until you get the sound you want.

You say lights flash? There are a lot of LED's on the unit and there are displays. Depending on what you mean by "lights" sends us on a whole different path. Remeber the effects ADD to the noise as they add into the buss to the amps. You should have the Effect to MAIN knobs not too high... say 12 o'clock. Same for the effect send knobs for the channels. If all the LED's flash, better stop using the unit as there is a power supply problem and damage will occur.
Please read my tip on here about the hazard of Channel A output when using Speakon to 1/4 inch speaker cables or adapters. The SHELL or SLEEVE of channel A cable is the HOT one, NOT the tip so never let that shell touch or connect to ground. The effect window when first powered should display a zero, not one... If it displays 1 at first, unit needs to be taken for repair as there is a defect.

Connect ALL interconnected equipment to the same receptacle or power conditioner source. Pro's run extension cord back to mixer if they have other stuff on stage. The speaker cables should connect to NOTHING other than speakers... do NOT try to tap off the daisy chain outputs of speakers for anything other than speakers. Use balanced lines and isolating DI boxes to avoid ground loops. Make sure to only poower this from a grounded receptacle.

There can be any number of reasons for this problem - solve it diagnostically by starting with something that you know is working and work through systematically to the other end.

1. Test a microphone on a separate amp to make sure it works okay. Check amp and speakers working. Check that all output cables from mixer to amp are working by testing separately.
2. Plug microphone into a channel on mixer. Also plug in headphones and turn headphone volume control up.
3. Make sure input sensitivity knob is turned up a bit (say half way) and main output faders (yellow) are up.
4. Check that channel is turned on (little button just above the channel fader- needs to be pressed down)
5. press pfl (pre-fade listen) button (next to button to switch channel on)- do you get any sound on main output or headphones or any indicator lights on mixer to show signal is getting that far (eitehr the individual channel metering lights or the main ones in the central section)?
6. turn off pfl - make sure channel fader (slider) is up - normal position is ) - about 3/4 of way up. Check lights again on individual channel and main output section - any signs?
7. Is the sub mix button for the channel pressed down - in which case you will need to bring sub mix (red) output faders up as well as main faders.
8. If you have got signs of signal on the individual channel but not main see if the channel has been routed somewhere odd (like a subgroup of channels).
9. Plug a working amp and speakers into one of the auxiliary outputs and use the relevant auxiliary send knob (on each channel just above the faders and pfl switches) to pan some signal to that auxiliary out - do you get anything? There is also a headphone socket for listening to the auxiliary channels (with a selector switch /knob to determine which one - make sure it is in the right position) try listening to the auxiliary output with headphones - anything? If yes the problem lies in the main output section.
10. Check that there is not a jack plug in the insert socket (to route signal through an external effects unit) without a matching return jack being plugged in - if appropriate is relevant effects unit switched on and correctly set up - if unsure remove the insert plug to take it out of the system.
11. Make sure any mute buttons are not switched in on main outputs.

You can download a full user manual here http://www.allen-heath.com/gl/gl2400

This is in general for Behringer mixers since you did NOT tell us a model number...

To use the effects you adjust the FX knob for EACH channel for the amount of the mic or input you want to send to effects from that channel. This is the "send" mix.

You dial in one of the effects based on the list near the effects selection window with the selector knob and the number will change and start flashing. You press down on the selection knob which will enter the new effects number and the number will be solid and not flashing.

Then there is a knob to select how much of the OUTPUT of the effects you want to go to the main and sometimes one for the amount to the monitors.

That is all there is to it. The effects can be gated by a foot switch input if you desire.

It is a good idea to include a model number as your thing is posted as if it is a PMP3000 mixer.

If your scanner is open squelched on one channel, try blocking that channel out. Some times a channel can get jammed if someone has a mic cue button stuck or something similar.
Try locking out that particular channel and see if you get your squelch control back.

You have to select an effect, push down the selector knob to lock it in. You have to send signal to the effect by turning up the effect in the "strip" above the slider. You have to turn up the effect sent to the main below the effect window, and finally use the effect slider to control the amount of effect. There may also be a button to toggle the effect on and off near the effect number window.